Heat exchangers can be employed in the gas turbine engine sector (e.g., the aerospace sector) for the purpose of transferring heat between a core air stream and a bypass stream. Air-to-air type heat exchangers have been explored for this purpose. Such heat exchangers may be configured to serve as an intercooler or as a bypass duct heat exchanger. These types of heat exchangers, however, can require complex ducting that adds system weight and costs. Accordingly, there is room for further improvements in this area.